Process of and means for depositing metals.



' U IT D sTATEs PATIENT OFFICE.

nueirs'rus nosnnnnne, or LONDON, ENGLAND.

v To allwhomitmayconcem: I

RRQiJESS OF AND MEANS FOR DEPOSITING METALS.

Specification of Letters Patent. Patented Sept.,20, 1910- No Drawing. Original application filed March 16, 1909, Serial No. 483,748. Dividedand this application filed August 2, 1910. Serial No. 575,115. x l v Be it known that I, AUGUSTUS ROSENBERG a subject of the King of Great Britain, and resident of London, W. 0., England, have invented a Process of and Means for Deposy Metals, of which the following 1s a iting specification.

This application-is a division of my application for patent for the same lnventlon,

filed March 16, 1909, SerialNo. 483,748.

This .invention relates to the art of coating or plating electrically conductive su'rfaces with metals and to that particular method in which the article is coated by the frictional application of a powder to its sur-'' face. My invention difi'ers however from such method inasmuch as it is based on the employment of a novel mixture of ingredients'containing all that is necessary, when the mixture is brought into contact with water, to set u, electrolytic action so that disposition of the metal is brought about by electrolytic action notwithstanding that no external source of current is employed. The process may be con" veniently carried into effect by dipping a wet rag into the mixture so as to cause it to take up or become loadedwith a 'suflicient quantity of-the mixture and then rubbing the mixture adhering to the rag onto the surface of the article to be coated and repeating the operatlon as often as necessary to obtain the desired result.

One-object of my invention is to provide a mixture whereby the electrolytic deposi-' tion may be carried out without the exercise of'any ski1l,and in an eflicient and economical mannelflso as to permit the wide.

and convement use of this powder for do-- mestic or household purposes.

Another object of the invention is to'provide a, mixture by means of which a firmly adherent and substantial deposit may be prothe deposition of metals and the use thereof 1 duced in the manner described.

A further object of my invention is to consists in the particular combination of-ingredients all in powdery form, for obtaining the. surface to be coatedl and a substance (or in solution) in the electrolyte, as the impart a fined in the ap nded claims.

A further ob ect of my invention consist in the employment, in combination-with the metal to be deposited,of a metal in its ele-' mentary state, electropositive with respect 'to which is capable of pro ucing an aqueous electrolyte when brought into contact with 1 water. In use, thesubstances in. suspension case may be, set up electrolytic action which. brings about the deposition of; metal upon the surface to be coated. The electropositivemetal may in some cases be the metal to be deposited. I

Another important feature of my invention consistsin the combination with'the ingredients of inert substances (either of mineral or organic nature.)- which by their presence will prevent remature interaction of the ingredlents which would otherwise take place or their chemical change previous to use.

A further feature of'myihvention consists in the use in the electroplating mixture of a substance 01' substances which acts (or act) either chemically or mechanically to polish to the surface of the metal deposited.

As an example of a mixture prepared in accordance with my invention I will give the formula of a mixture suitable for use in plating metals such as iron or copper with zinc; This formula is as follows:

Zinc dust (commercial) 45 parts. Ammonium sulfate 15 Magnesium l 3 Chalk 30 Talc powder 7 common metals generally usedfonplating. It is to be noted in general that lnevery case where the metal to be deposited is not, in' itself, employed as the electropositive element hereinafter referred to, the metal which is so employed as electropositive ele I ment must not only be electropositive with I respect to the metal to be deposited but also to the surface to be plated. I

'lhe'ammonium sulfate in the above formula constitutes, when moistened with water, the electrolyte. In this connection it may be noted that the use of an ammoniacal salt as an electrolyte is particu- I larly recommended when the surface to be plated is greasy, as the alkaline solution of plating operation.

the ammonia gas liberated in the reaction dissolves the grease and thus facilitates the The commercial zinc of the formula above given contains impurities, including the zinc oxid, but it is nevertheless quite suitable for use, as the impurities are not such as to sub stantially interfere with the necessary reactions, while the oxid isdissolved and the -zinc therein .deposited the same as in the case of the elemental zinc. In this connection it may be noted that in general the oxids of the metals to be deposited may be employed in place of these metals in elemental form, where an electropositive metal is also employed, and in the succeeding claims, where I have specified a metal in elemental form as the metal to be deposited, I do not mean to'exclude the oxid'of such metal.

The tale powder in the "above formula has the function of preventing the ammonium sulfate from acting upon the other ingredients in consequence of theabsorption of.

moisture from theatmosphere, and the use of this or an equivalent substance is an important feature of the invention, since it permits the mixture to be stored or to be exposed to the atmosphere for lengthy periods without substantial deterioration.

The chalk of the formula acts as a diluent or filling and retards the action of the elements of the compound on .each other,

thereby afi'ording the necessary time for the electrolytic action to occur in the best manner. The chalk is also useful, as it insures an alkaline reaction in the electrolyte. The chalk has a further mechanicalfunction which; will be referred to later.

In the above-described operation the chalk, in addition to the functions specifically described, acts as a mechanical polishing agent,

,suchas sugar, dextrin, and

so that the frictional application of theimixture results; first,.in the cleansing and pol ishing of the conductive surface; second, in the deposition of the zinc, and-third, in polishing the newly deposited zinc.

In addition to the use of mechanical polishing agents, I may make use of agents having a chemical effect resulting in a polished surface on the deposited metal. For

thispurpose I have found carbohydrates, gum to be eifect ve when-employed in'a' mixture in which the electrolyte is a sulfate or. a double salt containingthe radicle S0,, the later. prob- 'gredi ents hereiriabove referre ably forming with the carbon ofthe carbohydrates, carbon disulfid, a substance which is well known to have a polishing or brightening effect upon electrically deposited metal. v

The friction employed-in applying my electro-plating mixture is useful in several ways. It acts, first, to assist the cleaning of the surface to be plated. It assists the chemical and electrical actions bybringing the elements of the mixture in close contact and by mechanically depolarizing the metallie elements 'of the electric couples by which the electric current is generated. Fi-

nally it acts, as before pointed out, to polish' the deposited metal.

While the talc powder acts as above pointsuitable. The most convenient way in which to coat the particles is to moisten them with a solution of wax or resin in gasolene or other volatile solvent, and then dry out-the solvent, after which the coated metal is mixed with the other ingredients of the mixture. When the mixture is used the friction employed in the application quickly causes the removal of the coating material and the exposure'of the metal to the electrolyte. I The coating of the electropositivemetal has the further advantage (where the metal to be deposited is present in elemental form, as in the formula hereinbefore given for zinc-plating) that it prevents chemical action upon the electropositive metal upon the first wetting of the mixture, and this affords opportunity for the metal in suspension to be deposited.

In addition to the ingredients hereinbefore mentioned, it may sometimes be desirable to add certain acld substances, "such as boracio acid, or alkalies, such as sodium carbonate, 1n order to givethe com osit-ioneitheran acid reaction or an alka ine re-. action, as. may be desirable under c1rcumv stances well known to'those skilled in the art of electroplating. My invention is appli almost any metal upo zinc upon zinc, or up tale for depositing it will be understood that the severafinr.

tself, for example, an fother metalgejn-Y' erallyused in the'art{of-;.e ectroplating and d to may be" 13:0

as so many minute anodes eachisetting up local circulations of. electric current. The circuits are so excessivelytsmall, sd exceedingly near together and so numerous that they cannot be separately observed, but each causes a deposit of the metal to be deposited upon 'the'cathode surface. Owing to the number of small currents generated these, as they leave the liquid, deposit a film of the metal to be deposited over the surface to be coated.

The foregoing description of the manner of carrying out my invention is for the purpose of illustration only and is not intended to be exclusive.

It is also obviousthat many modifications and chan es may be made in my invention without same, and I do not desire to limit myself to the particular features described, but

\Vhat I- claim and desire to secure by Letters Patent is:

l. The method of electroplating which consists in the frictional application to an electrically conductive surface, in the pres- 40 ence of an electrolyte containing in suspension the metal to be deposited, of a second metal clectropositive with respect to both said surface and said metal in suspension, said electropositive metal being in elemental and comminnted form.

The. method of electroplating which consists in the application to an electricallyconductive surface, in the presence of an electrolyte, of the metal to be deposited together with a polishing agent;

The method of electroplating which consists in the frictional application, to an electrically conductive surface, in the pres ence of an electrolyte, of the. metal to be deposited, together with amechanical polishing agent 4. The method of electroplating which consists in the frictional application, to an electrically conductive surface, of a mixture 0 comprising an electrolyte, a carbohydrate,

and a mctalelectropositive with respect to said surface and in elemental and comminuted form.

The method of electro lating which consists in the frictional app ication, to an -el callv. voriducili Lame t an m aniet e etmpeslt Slllftlc 'gttlldf-gIn} eleu elital and connni uutcd; :fmi hm; I f 3 1'. w The; met o of, e ec ropl t ng which teans ica1 y conducti eSurface; nj hep esence eta Solid .c nsistsini suspension ithe, meta toi Wco'nd mtahf departing from the spirit of the.

jl i fi ri dc: sali di umw i wi ;respec @wsa lei te y hevapp at n,

diluent and of an electfirolyt containing, in;

udepositecl of a p tlCtlfOPOSltl YGgWltll respect jto both. lSllIdnS lTfiK andc h meta lin usp n- ;sion,- said gelectrdpositive metal being in elerxentaL-and Icoimninutedform;

7. The -method of. electroplating V which consists in'the application, to an electrically conductive surface, Qa-anixture comprising comminuted, elemental magnesium, and an electrolyte having in suspension the metal to be deposited.

8. The method of electroplating which consists in the frictional a plication, to an electrically conductive sur ace, in the presence of an electrolyte holding in suspension the metal to be deposited, of comminuted elemental magnesium.

9. The method of manufacturing an electroplating mixture which consists in coating electropositive metal particles in the ole mentary and comminuted form with a solu-- tion of protective material, drying said particles, and mixing them with the metal to be deposited. 10. The method of manufacturing an electroplating mixture which consists in coating metal articles with a protective material, and mixing the coated particles with a dry pulverulent material capable of forming an electrolyte.

11.. The method of electroplating, consisting in the frictional application to a conductive surface in the presence of moisture, of a mixture of pnlverulent materials including the metal to be deposited, an electropositive metal and a substance capable of yielding, in conjunction with moisture, an aqueous electrolyte. 1

12. The method'of electroplating, consisting in the frictional application to a conductive surface in the presence of moisture, of a mixture containiny pulverulent materials, including the metal to be deposited, an electropositive metal present in the elementary state and'a substance capable of yielding, in conjunction with moisture,- aud an aqueous electrolyte.

13. As a new article of manufacture for depositing a metal upon a conductive surface, a mixture of pulvcrulent materials including the metal to be deposited, an electropositive metal, and a substance capable of yielding, in conjunction with moisture, an aqueous electrolyte.

14. As a new article of manufacture. for depositing a metal on :bcomluctivc surface,

face,am1xtureofp a mixture of igherulentmaterials including the metal to. deposited in its elementary form, an electropositive metal, and a substance capableof yielding, in conjunction.

with moisture, an ueous electrol" e. p

15.=As' a new article pf man for depositing a metal u n a conductive suns cludingthe metal to be deposited an electro-' positive metal, and a salt.

16. As a new article of 'manufacture for depositing a metal u a conductive surface, a mixture of p verulent materials including the metal to be deposited, an electroposltive metal, a salt, and a substance capable of preventing the 7 absorption of moisture. I 1

17. As a new article of manufacture for verulent materials inl depositing a metal upon a conductivesun face, a nuxtul e cf pulvelr'ulentin.-

cluding the metal to be depodted in' eleelectropositive metal, and

ment form, an a m 'c'salt.

18; As a newfarticle of manufacture for p siting avmetal upon a conductive sub a mixture of pulverulentface,

eluding the ,metalte be deposited in elemental-y form, an electropositive metal, a metallic salt, and a substance capable of preventing the absorption of moisture by 30 

